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<table width="100%" summary="page for daphnia"><tr><td>daphnia</td><td align="right">R Documentation</td></tr></table>

<h2>&lsquo;Daphnia Magna&rsquo; Data</h2>

<h3>Description</h3>


<p>The <code>daphnia</code> data frame has 136 rows and 2 columns.
</p>
<p>Ecotoxicity study to assess the impact of the herbicide dinoseb on 
the survival of <EM>Daphnia magna</EM> Strauss, 1820, a 
micro-crustacean widely used as test organism in aquatic 
ecotoxicological assays.  The design of the experiment includes 35 
irregularly spaced concentrations ranging from 0.006 to 11.3 mg/l 
and a control group.  The upper endpoint of 11.3 mg/l is the highest
concentration at which the test substance is soluble in the test 
medium.  The number of replicates per concentration varies from 1 to
11 experimental units.  The survival time is measured in days.
</p>


<h3>Usage</h3>

<pre>data(daphnia)</pre>


<h3>Format</h3>


<p>This data frame contains the following columns:
</p>

<dl>
<dt><code>conc</code></dt><dd>
<p>the tested concentration (mg/l);
</p>
</dd>    
<dt><code>time</code></dt><dd>
<p>the survival time in days.
</p>
</dd>
</dl>



<h3>Source</h3>


<p>The data were obtained from
</p>
<p>Ch\'evre, N. (2000) <EM>Etude et mod\'elisation des effets 
\'ecotoxiques d'un micropolluant organique sur</EM> Daphnia magna
<EM>et</EM> Pseudokirchneriella subcapitata (in French).  Ph.D. 
Thesis N. 2117, Department of Rural Engineering, Swiss Federal 
Institute of Technology Lausanne.
</p>


<h3>References</h3>


<p>Brazzale, A.R. (2000) <EM>Practical Small-Sample Parametric 
Inference</EM>.  Ph.D. Thesis N. 2230, Department of Mathematics, Swiss
Federal Institute of Technology Lausanne.  Section 5.3, Example 5.
</p>
<p>Ch\'evre, N., Becker-van Slooten, K., Tarradellas, J., Brazzale, 
A. R., Behra, R. and Guettinger, H. (2001) Effects of dinoseb on the
entire life-cycle of <EM>Daphnia  magna</EM>.  Part II: Modelling of 
survival and proposal of an alternative to 
No-Observed-Effect-Concentration (NOEC).  <EM>Environmental 
Toxicology and Chemistry</EM>, <B>21</B>, 828&ndash;833.  
</p>


<h3>Examples</h3>

<pre>
data(daphnia)
attach(daphnia)
plot(conc, time, xlab = "test concentration (mg/l)", 
     ylab = "survival time (d)", log = "y")
detach()
</pre>


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